Intraventricular injections of progesterone (P4) will be made into laying hens at either 18 h prior to ovulation of the first follicle of a sequence (C1 follicle) (6h after onset of light) or at 24 h prior to ovulation of the C1 follicle (2 h after onset of light). The hens will receive 14L:10D. The differences between control-injected and P4-injected hens will be noted for: time of ovulation, time and amplitude of LH, P4 and testosterone (T) peak concentrations. We will start injections of antibodies to P4 and to T at 8 h prior to ovulation and note effects on ovulation LH, T, and P peaks for bound and free P and T. Another P4 or T will be injected into follicles 10-12 h prior to the time of ovulation and the effect on ovulation noted.